More than 300 firefighters scrambled to fight a violent blaze outside of Berlin on Friday, forcing the complete evacuation of the villages of Frohnsdorf, Klausdorf and Tiefenbrunnen.

Loudspeaker announcements told residents to leave their homes and take only their most important possessions, such as identification papers and medicines.

Most of the 540 villagers stayed with relatives, officials said, although several had to spend the night at a town hall in the nearby village of Treuenbrietzen.

"We've had forest fires before but never of this magnitude," said Treuenbrietzen Mayor Michael Knappe.

Isolated showers were predicted for parts of Berlin and Brandenburg, but meteorologists could not predict whether the rain would fall on burning areas.

The fire has already begun to affect regional train traffic between Wannsee and Jüterbog, as well as some trains heading from the area throughout eastern Germany. The blaze has not, however, affected air travel into and out of Berlin airports.

Later on Friday, Brandenburg Interior Minister Karl-Heinz Schröter told the press that the fire had been "dampened," but that a decision as to whether residents would be allowed to return to the evacuated villages would not come before midday.

Christian Stein, a local official for the district of Potsdam-Mittelmark, told reporters that Thursday's fires broke out in several places and had expanded to cover a total area of around 300 hectares, an area about the size of 400 football fields. Rising plumes of smoke were reportedly visible from as far as 10 kilometers (around 6 miles) away.

"Our main goal is still to protect the evacuated areas from the flames," Stein said. "The fire still has not been pushed back, but it also hasn't taken a building with it."

Raimund Engel, the Brandenburg commissioner overseeing forest fires, however, said he was expecting major damage. The blaze had developed into a "full fire" that was no longer just burning the ground but had also spread into the treetops, he added.

Authorities also warned that strong winds could fan ash and smoke from the villages all the way to the southern districts of Berlin.

Brandenburg has endured a particularly hot summer this year, and rainfall has been scarce for several months. Vast areas have dried up as a result, increasing the risk of fires.

Engel also warned emergency services could face even greater risks the longer that fires continued to rage. The blaze is located in an area laden with munitions, located between the districts of Potsdam-Mittelmark and Teltow-Fläming. A regional control center for Brandenburg said there had already been multiple explosions. Undetonated World War II bombs are frequently unearthed in Germany.

"There are places we cannot get to," an emergency service spokesman said, adding that firefighters were forced to stay on cleared roads in some areas.

This article originally appeared on DW.com. Its content was created separately to USA TODAY.